1. Field of the Invention
This invention relates to a knife of the folding blade type suitable for carrying in a pocket or handbag. In particular, this invention relates to such pocket-knife which is constructed so as to lock the blade in extended or open position for greater safety in use, to minimize any injuries to the hands and fingers of the user when the blade is folded into the handle in closed position, and to minimize damage to the clothing when it is folded and carried in the pocket.
2. Description of the Prior Art
Pocket-knives having foldable locking blades are known in the prior art. Such knives have been made and used for many years and numerous designs have been proposed for accomplishing positive locking of the blade and for easier locking and unlocking of the blade. Generally pocket-knives having a foldable blade do not have a locking mechanism for locking the blade in an extended position. On the other hand, locking mechanisms are known for locking the blade in closed position to be held safely closed in the handle by a beam spring.
The knife disclosed in U.S. Pat. No. 4,040,181 to Johnson shows a locking rocker arm arranged in the back of the handle. The arm is slidingly mounted for movement in the handle. Yet to swing the blade into closed position, a person must change the position of the knife in his hand and further must use both hands in order to press down the rocker arm in the back and then swing the blade in the front of the handle and back between the side covers.
Reference is also made to the U.S. Pat. No. 924,070 to Holman. This construction has a blade pivoted in a handle on a butt pin. When the blade is turned into open position, a guard is folded into the handle and comes into contact with the butt of the blade and holds it. A catch is provided to slide in the handle to engage the guard for firm seating.
German utility model DE-GM No. 17 15 228 shows a pocket-knife with a locking blade provided with a pawl arranged in a side cover to lock the blade in extended position by means of an end pin and a coil spring to urge the blade into locking position. As the blade is pulled out of the handle or returned between the side covers, the user must not change the position of the knife in his hands. The principal disadvantage of this prior art design is that the blade has resilient means for returning the blade to the safe position upon closing. The blade can swing out and may hurt the person and cut the clothing.
Another example of the prior art is a design which relates to a pocket-knife having a locking mechanism that must be released in the open and the closed position of the blade --the latter being unconventional for most knife users. As a result, many users break fingernails when attempting to open the locked blade for use.
Reference is lastly made to another defect of some prior art designs wherein the operating parts of the locking mechanism are open to the exterior. When such knives are used by outdoorsmen, for example, campers, hunters and fishermen, debris, such as sand and wood chips, quickly work in between the parts, including the spring components, and interfere with proper operation. The gaps are usually small and inaccessible so that it is very difficult to clean them.